Japanese manufacturer The Polyplastics Group (Polyplastics) has announced a high-performance material that it says offers heat resistance and thermal insulation properties for EV lithium-ion batteries.

The firm says that DURAFIDE (R) PPS 6150T73 “significantly improves” thermal and electric insulation properties during thermal runaway without the use of inorganic insulative sheet structures.

The material maintains the insulation properties of busbars and module covers after being left in environments of 1,000 °C for 30 minutes.

Though rare, EV battery fires can pose serious risks as they are difficult to extinguish and in some instances, damaged battery packs have been known to reignite weeks after a fire has occurred.

Excessive heat is caused by thermal runway, when a battery enters an uncontrollable self-heating state.  During a thermal runaway event, a lithium-ion cell can reach temperatures of 800°C to 1,000°C.

As a safety measure, structural insulative sheets and plates have been previously used to reduce energy transfer from one cell to another. However, they increase weight and consume space.

Polyplastics says that in addition to greater heat resistance, DURAFIDE (R) PPS 6150T73 has optimal properties for components such as module covers and busbars.